The Singular Genomics adapter sequences are described in our reference guide titled Adapters and Indices for the G4 Sequencing Platform.
Singular adapters are used during library preparation to add several functional nucleotide tags to each end of the inserts to be sequenced:
At the 5’ ends, Singular’s proprietary platform sequences S1 and S2 are attached as anchors for the formation of clusters on the flow cell. The SP1 and SP2 tags, which are compatible with sequencing primers used in many existing applications, are positioned directly adjacent to the insert. When constructing libraries for multiplexed reads, index 1 and index 2 sequences are placed in between S1 and SP1, and S2 and SP2 respectively.